Page 40: of Offshore Engineer Magazine (Feb/Mar 2015)

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Drilling

Industry set for new MPD guidelines

MPD equipment required

In the last decade, however, drillers for a deepwater rig integration.

Jerry Lee reports on new have utilized managed pressure drilling

Photo from Weatherford.

guidelines for managed (MPD) to address this. MPD involves using lower density mud, a surface choke pressure drilling operations manifold and surface back pressure to American Petroleum Institute (API) are due out this year from both dynamically control the annular pres- releasing their own set of MPD class rules

ABS and API.

sure profle. By adjusting the surface and recommended practices at the end of backpressure with the choke, proper 2H 2015.

rilling is becoming increas- equivalent circulating density (ECD) can “API standards are recommended prac- ingly diffcult as companies are be maintained to stay within the frac- tices for conducting managed pressure

D reaching further into deeper ture gradient. MPD allows the driller to drilling operations that apply across the reservoirs. Drilling deeper poses a chal- quickly respond to and control wellbore board,” says CJ Bernard, global business lenge to engineers as wells become ever conditions, while having the added development manager at Halliburton’s more complex. One issue is the narrow beneft of extending the casing setting Sperry Drilling GeoBalance group.

DNV pressure window, or fracture gradient, point or removing the need for a section “Everything from the planning aspects, to well control event identifcation, of casing. that must be navigated to reach certain In 2011, DNV became the frst classif- response and management, to equipment As wells targeting deeper, more chal- reservoirs. cation society to have general rules for design, selection and testing, to equip- lenging reservoirs become common The fracture gradient is the pressure MPD systems on board DNV-classes drill- ment requirements, so they have to do place, MPD is used more frequently. This range between the pore pressure and frac- ing units with the class notation Drill(N). more specifcally with MPD operations. technique, originally used onshore, is ture pressure that exists for a particular A more detailed set of requirements were “Whereas classifcation societies (ABS, becoming a viable option offshore, thus formation. The driller will typically aim released in the update of DNV-OS-E101

DNV & Lloyds) speak to requirements of changing the initial environment for to keep the annular hydrostatic pressure in 2013. This revision is currently being the equipment as it relates to interactions which the MPD systems and the associ- above the pore pressure, to prevent a used to classify and certifed MPD sys- with the other ‘classed’ drilling equip- ated equipment were developed. kick, and below the fracture pressure, to tem, says DNV GL’s Arne Handal, Ph.D, ment on the rig,” says Bernard, who also Recognizing this trend and the need prevent formation damage, which may principal engineer for drilling and well serves as class society task force chair on to ensure operations are performed in a result in fuid loss. Such obstacles may intervention, in a comment to OE.

the International Association of Drilling safe environment, DNV GL, the American prevent wells from being drilled using “The new standard includes require-

Contractors (IADC) MPD committee. Bureau of Shipping (ABS) and the conventional techniques. ments for managed pressure drilling

February 2015 | OE oedigital.com 42 042_OE0215_D&C1_Jerry.indd 42 1/20/15 6:21 PM